Influenza-like illness in Norway: clinical course, attitudes towards vaccination and preventive measures during the 2009 pandemic

OBJECTIVES

To document clinical characteristics of influenza-like illness, reported use of health preventive measures and attitudes towards vaccination among patients with influenza-like illness in general practice during the influenza pandemic in 2009.

METHODS

Cross-sectional survey in general practice. Patients, who were identified as having influenza-like illness during the peak of the influenza pandemic activity in Norway, were eligible for inclusion in the study. A questionnaire was sent 2-4 weeks after the patients visit to the GP with influenza-like illness diagnosis during October to December 2009, from general practices in Norway. A sample of responders >18 years also had a blood test to check for serological response to the pandemic H1N1 virus.

RESULTS

Questionnaires were sent to 1324 patients, and 357 (27%) were returned. Fever (91% versus 49%, P < 0.01), cough (85% versus 73%, P = 0.016) and gastrointestinal symptoms (58% versus 38%, P < 0.01) were more frequent in the age group <18 years compared to older patients. Serological H1N1 responses were analysed in 72 patients; 34 (47%) were positive (haemagglutination inhibition assay titres ≥ 40). There were no statistically significant differences in symptoms between seropositive and seronegative patients. Women reported better adherence to personal protective measures, such as hand washing and cough etiquette than men. Women were also more concerned about possible adverse effects of the pandemic influenza vaccine than men.

CONCLUSIONS

Discrimination between influenza and other viral upper respiratory tract infections is difficult in daily clinical practice, even during an influenza pandemic. A gender difference was found in reported precautions to prevent influenza.

Mechanism of action of the suppression of influenza virus replication by Ko-Ken Tang through inhibition of the phosphatidylinositol 3-kinase/Akt signaling pathway and viral RNP nuclear export

AIMS OF THE STUDY

Ko-Ken Tang (KKT, aka kakkon-to), a conventional Chinese herbal medicine, has been used for the treatment of the common cold, fever and influenza virus infection. However, the underlying mechanism of its activity against influenza virus infection remains elusive. In this study, the antiviral effect and its underlying mechanism was evaluated, including the investigation of anti-influenza virus activity of KKT on MDCK cells and corresponding mechanism related to phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway and its consecutive viral RNP nuclear export.

MATERIALS AND METHODS

The antiviral activity of non-toxic concentration of KKT was examined against various strains of influenza virus and enterovirus 71 by neutralization assay. PI3K/Akt signaling activated by influenza virus was inspected in A549 cells by western blot. Inhibition of influenza polymerase activity by KKT was measured with plasmid-based reverse genetics using primer extension assay and luciferase reporter assay. Inhibition of viral vRNP nuclear export was demonstrated by laser confocal microscopy and interspecies heterokaryon assay.

RESULTS

KKT inhibits influenza virus replication but not entry, and it exhibits a broad spectrum inhibitory activity against human influenza A viruses and enterovirus 71. KKT does not inhibit viral polymerase activity but directly blocks the virus-induced phosphatidylinositol 3-kinase/Akt signaling pathway, which in turns causes retention of viral nucleoprotein in the nucleus, thereby interfering with virus propagation. The inhibition by KKT of the nuclear export of viral protein was further confirmed by heterokaryon assay.

CONCLUSIONS

The results obtained in this study give scientific support to KKT for the treatment of influenza virus infection. KKT could be of potential use in the management of seasonal pandemic influenza virus infection in addition to other clinically available drugs.

Hygiene campaign autumn 2009--fewer cases of infection at the emergency centre?

BACKGROUND

Prompted by the H1N1 influenza epidemic in autumn 2009, Norwegian health authorities launched a campaign for better hygiene. We wanted to investigate whether there was any change in the out-of-hours contact rate for infectious diseases during this campaign.

MATERIAL AND METHODS

The material consisted of remuneration claims from all doctors doing out-of-hours work during the years 2006-2009. The contact rates for nine diagnoses of infectious illness in autumn 2009 were compared with a corresponding mean from the years 2006-2008.

RESULTS

The contact rate for influenza was ten times higher in autumn 2009 than in the three preceding years. During the same period there was a significant reduction in conjunctivitis (contact rate ratio 0.74), otitis (0.73), sinusitis (0.70), throat infections (0.79), pneumonia (0.70) and intestinal infections (0.82). There were small changes in the contact rates for acute upper respiratory tract infections and urinary tract infections, but in December there was also a clear reduction in acute upper respiratory tract infections (0.61).

INTERPRETATION

The reduced contact rates for infectious diseases may be ascribed to an effect of the campaign, but other factors may also have contributed to this result.